Herbal medicines, such as St. John's wort and
high doses of echinacea.

A semen sample that gets cold. The sperm
motility value will be inaccurately low if the semen sample gets
cold.

Exposure to radiation, some chemicals (such as certain
pesticides or spermicides), and prolonged heat exposure.

An
incomplete semen sample. This is more common if a sample is collected by
methods other than masturbation.

Not ejaculating for several days.
This may affect the semen volume.

What To Think About

A home test kit to determine sperm count has been approved by the U.S. Food and Drug Administration (FDA). This test can help a man find out if he has fertility problems.

A semen sample collected at home must be
received at the laboratory or clinic within 1 hour. Keep the sample out of
direct sunlight and do not allow it to get cold or hot. If it is a cold day,
carry the semen sample container against your body to keep it as close to body
temperature as possible. Do not refrigerate the semen
sample.

Consistently detecting sperm in the semen of a man who has
had a vasectomy means that his surgery was not successful, and another form
of
birth control should be used to prevent pregnancy. A
low number of sperm may be present in a semen sample taken right after a
vasectomy. But sperm should not be present in subsequent samples.

A man whose mother took the medicine
diethylstilbestrol (DES) during her pregnancy with him
has a greater-than-normal risk of being unable to father a child
(infertile).

Other fertility testing,
including sperm penetration, the presence of antisperm antibodies, or analysis
after sexual intercourse (postcoital), may be recommended for infertility
problems. To learn more, see the topic
Infertility Testing.